When placing multiple points on a single BasicGoogleMap webpart, when you click each of the points to bring up the info window, it does not close the previous one (default action with Google Maps). When I looked into the JavaScript (CMSWebParts\Mapx\Basic\BasicGoogleMaps_Files\GoogleMap.js the addGoogleMarker() function creates a new instance of the InfoWindow each time vs, just setting the content. I'm guessing this is by design/default although it should function as Google Maps does.

Here is the code I used and it worked perfect:

// Create a single info window object
var wname = new google.maps.InfoWindow({});
function addGoogleMarker(map, latitude, longitude, title, content, zoom, iconURL) {
    // Initialize point coordinates
    var point = new google.maps.LatLng(latitude, longitude);
    // Create Marker object
    var marker = new google.maps.Marker({
        map: map,
        position: point,
        title: title,
        icon: iconURL
    });
    // Register click event
    google.maps.event.addListener(marker, 'click', function() {
        map.setCenter(point);
        var oZoom = map.getZoom();
        if (oZoom != zoom) { map.setZoom(zoom); }
        // set the content when clicked
        wname.setContent(content);
        wname.open(map, marker);
    });
}